There is known a device in a vehicle including a torque converter having a lockup clutch between an engine and a transmission. The device is configured to presume a contact timing at which the lockup clutch has a lockup capacity, based on a variation of an engine speed (for example, a patent document 1).
However, in this conventional device, the contact timing is presumed based on the variation of the engine speed. Accordingly, the contact timing may be erroneously presumed in a drive state by an accelerator depression. When a ramp control to engage the lockup clutch is started based on the contact timing which is deviated from an appropriate timing at which the lockup clutch starts to have a lockup capacity (the lock capacity is started to be generated), a vehicle behavior variation is generated due to a forward/rearward G variation.
That is, in an accelerator foot release coast state, there is no variation of a turbine rotation speed, or there is small variation of the turbine rotation speed. Accordingly, it is possible to presume the contact timing by the variation of the engine speed. However, for example, when the reacceleration is performed by the accelerator depression from a coast deceleration traveling, the engine speed and the turbine rotation speed are varied due to the drive state. Accordingly, the contact timing may be erroneously presumed by monitoring the only variation of the engine speed.